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Lighting, well-being and work performance: A review of the literature
Commissioned White Paper Report for Philips International
Event-based Face Detection and Tracking in the Blink of an Eye
We present the first purely event-based method for face detection using the
high temporal resolution of an event-based camera. We will rely on a new
feature that has never been used for such a task that relies on detecting eye
blinks. Eye blinks are a unique natural dynamic signature of human faces that
is captured well by event-based sensors that rely on relative changes of
luminance. Although an eye blink can be captured with conventional cameras, we
will show that the dynamics of eye blinks combined with the fact that two eyes
act simultaneously allows to derive a robust methodology for face detection at
a low computational cost and high temporal resolution. We show that eye blinks
have a unique temporal signature over time that can be easily detected by
correlating the acquired local activity with a generic temporal model of eye
blinks that has been generated from a wide population of users. We furthermore
show that once the face is reliably detected it is possible to apply a
probabilistic framework to track the spatial position of a face for each
incoming event while updating the position of trackers. Results are shown for
several indoor and outdoor experiments. We will also release an annotated data
set that can be used for future work on the topic
Estudo experimental do comportamento ocular em trabalhadores administrativos como um indicador de conforto visual em situação de risco de encadeamento
The daylight impact on the visual environment is fundamental on visual display terminal work (VDT). Visual performance and visual comfort should be considered for equal. The study (n=16) was performed at the experimental lighting laboratory. Office work with VDT was evaluated using STROOP task in two orientations: (with/without solar presence in the visual field). Our hypothesis states the existence of a relationship between ocular behavior and visual comfort of workers. An eye-tracker was employed in order to record the ocular gestural parameters: blinks, direction of gaze, eye aperture (Degree of eye?s openness) and pupil size, which were correlated with the vertical illuminance at the eye. Visual comfort was assessed with Glare Sensation Vote. Results indicate a strong negative linear correlation between eye illuminance and the degree of eye?s openness in the direct sunlight scenario (p=-0.636; s=0.008) and in diffuse light scenario (p=-0.661; s=0.005), that could be the main predictor of visual discomfort. This experiment allowed us to explore eye behavior patterns that could be visual comfort indices under glare risk situations.O impacto a luz do dia no ambiente visual é fundamental para o trabalho no Ecrã de
Visualização de Dados (EDV). Desempenho visual e conforto visual devem ser considerados em igual. O estudo (n = 16) foi realizado no laboratório experimental de iluminação. O trabalho de escritório com EDV foi avaliado utilizando a tarefa de Stroop em duas orientações: (com / sem presença solar no campo visual). A nossa hipótese afirma a existência de uma relação entre o comportamento ocular e
conforto visual dos trabalhadores. Um “eye-tracker” foi desenvolvido para gravar os parâmetros gestuais oculares: pestanejar, direção do olhar, abertura dos olhos (Grau de abertura do olho) e tamanho da pupila, que foram correlacionados com a iluminância vertical no olho. Conforto visual foi avaliado com a escala de sensação de encadeamento. Os resultados indicam uma correlação linear negativa forte entre a luminosidade dos olhos e do grau de abertura de olho no cenário de luz solar
direta (p = -0,636; s = 0,008) e no cenário de luz difusa (p = -0,661; s = 0,005), que poderia ser o principal preditor de desconforto visual. Esta experiência permitiu-nos explorar padrões de comportamento do olho que poderiam ser os índices de conforto visual em situação de risco de encadeamento.Fil: Yamin Garretón, Julieta Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Rodriguez, Roberto Germán. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Pattini, Andrea Elvira. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentin
Human experience in the natural and built environment : implications for research policy and practice
22nd IAPS conference. Edited book of abstracts. 427 pp. University of Strathclyde, Sheffield and West of Scotland Publication. ISBN: 978-0-94-764988-3
Light environment - A. Visible light. B. Ultraviolet light
Visible and ultraviolet light environment as related to human performance and safety during space mission
The impact of fluorescent and LED lighting on student attitudes and behavior in the classroom
Abstract
Introduction: This study examined empirical research on the effects of high correlated color temperature
light-emitting diodes (LED) and fluorescent lighting on students in the classroom. LED is becoming the
most recent lighting option for optimal energy efficiency over fluorescent technology.
Background: A review of the literature indicates correlated color temperature (CCT) of lighting has nonvisual effects on students, with higher CCT positively impacting attitudes and behavior. The review also
revealed current studies regarding dynamic or tunable lighting that adjusts CCT based on desired activity
and mood. Data from an original survey analyzed teacher insights and perceptions regarding student
attitudes and behaviors associated with existing classroom lighting and the impact of higher color
temperature LED.
Methods: Participants were pre-K through high school qualified teachers from three schools and/or
personal contacts of the principal investigator. Seventy-five teachers responded to the online questionnaire.
The survey data suggests teachers perceive higher color temperature lighting positively impacts student
alertness, attitude, and energy level; and adjusting light levels throughout a school day positively impacts
student engagement.
Results and conclusion: Results supported the perception of higher correlated color temperature lighting
positively impacting alertness, attitude, and energy level. Findings also supported the ability to change
light levels throughout the school day to positively impact student engagement and mood. There were
mixed results regarding higher correlated color temperature impacting attention and on-task/off- task
behaviors. Results regarding the impact of sound and flickering from fluorescent lights were not
significant
Human Contrast Threshold and Astronomical Visibility
The standard visibility model in light pollution studies is the formula of
Hecht (1947), as used e.g. by Schaefer (1990). However it is applicable only to
point sources and is shown to be of limited accuracy. A new visibility model is
presented for uniform achromatic targets of any size against background
luminances ranging from zero to full daylight, produced by a systematic
procedure applicable to any appropriate data set (e.g Blackwell (1946)), and
based on a simple but previously unrecognized empirical relation between
contrast threshold and adaptation luminance. The scotopic luminance correction
for variable spectral radiance (colour index) is calculated. For point sources
the model is more accurate than Hecht's formula and is verified using
telescopic data collected at Mount Wilson by Bowen (1947), enabling the sky
brightness at that time to be determined. The result is darker than the
calculation by Garstang (2004), implying that light pollution grew more rapidly
in subsequent decades than has been supposed. The model is applied to the
nebular observations of William Herschel, enabling his visual performance to be
quantified. Proposals are made regarding sky quality indicators for public use.Comment: 21 pages, 18 figures, 1 table. Accepted in MNRA
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